JPH06188777A - High frequency tuning receiver - Google Patents

Abstract

PURPOSE:To select and receive a radio wave in a frequency range by performing highly selective tuning to the desired radio wave and controlling oscillation of specified local oscillation frequency. CONSTITUTION:A phase-locked oscillation loop consisting of a phase comparator 4 and succeeding units receives a received signal by frequency selective tuning. Outputs of local oscillators (20, 19, and 11) are inputted to frequency converters 7 and 9 and the phase is locked tuning to the input signal frequency of the phase comparator 4 corresponding to the sum of the local oscillation frequency and an intermediate frequency. The phase-locked loop composed of the phase comparator 4, a control filter 5, a VCO 6, a converter 7, an IFA 8, a converter 9, and a band amplifier 10 is used as a selective tuning type high frequency tuning amplifier determined principally by the band of the amplifier 8. Further, the output of the amplifier 8 is inputted to an angular modulation detector 8c through an amplitude limiting amplifier 8b to obtain a demodulated signal 25.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to an angle-modulated signal receiving device for satellite broadcasting television radio waves and the like, and is used in a receiving device for performing selective tuning and frequency conversion of a desired signal for reception to improve the receiving performance.

[0002]

2. Description of the Related Art Some broadcast radio waves existing in a reception signal band are frequency-converted into a first intermediate frequency band by an oscillation frequency of a first local oscillator, and further designated by a second local oscillator to selectively receive desired broadcast radio waves. The selected local oscillation frequency is used to select the desired signal and perform the frequency conversion to the second intermediate frequency. Further, it is technically difficult to perform highly selective tuning reception control and frequency conversion for a desired signal at a high frequency.

[0003]

With the prior art, it is difficult to perform high-selective tuning with respect to a desired radio wave at a high frequency (500 MHZ or more). Therefore, in a satellite TV radio wave or the like, the frequency is adjusted to an appropriate frequency band by using the first local oscillator. After conversion, the desired signal is selectively received. In this case, there have been problems such as frequency stability, intermodulation and intermodulation distortion between broadcast waves, deterioration of reception performance and complexity of the device. INDUSTRIAL APPLICABILITY The present invention makes it possible to configure a device for highly selective reception of radio waves in a frequency region, which has been impossible in the past, by performing highly selective tuning of desired radio waves and controlling oscillation of a specified local oscillation frequency. The present invention relates to a receiver which has been improved.

[0004]

As shown in FIG. 1, a control signal 24 for setting a local oscillation frequency, a designated clock generator 22 and a device 1 for generating a designated local oscillation frequency.
1 is used to oscillate the local oscillation frequency for selecting the desired reception frequency, and the local oscillator output drives the frequency converter (down converter), 7 and frequency converter (up converter) 9 that form a phase locked loop. The present invention relates to a phase-locked oscillator 6 synchronized with an input desired signal frequency, an intermediate frequency band amplifier constituting this phase-locked loop, and a receiving device for extracting a received signal as an output of 8 and demodulating it at a subsequent stage. In other words, if the local oscillation frequency is set, a phase-locked loop that selectively tunes to a signal of a desired reception frequency that differs only by the intermediate frequency is configured, and a narrow band that tunes to an input signal wave having a band determined by the intermediate frequency band and the control filter 5. Selection characteristics are possible.

[0005]

In a heterodyne type receiver for frequency conversion, it is very difficult for a general receiver to perform target band selective amplification at the center of the received signal frequency and then accurately perform frequency conversion to the center frequency of the intermediate frequency band amplifier. . Further, when the received signal frequency becomes higher, it is impossible to construct a receiver in which the selectivity is improved so that the tuning and radiation of the high frequency stage and the center frequency of the intermediate frequency filter of the frequency converted signal always match. However, as shown in FIG. 1 of the present invention, in the phase-locked oscillation loop synchronized with the input signal frequency, the intermediate frequency band filter, 8 and two frequency converters, and the frequency converter using 7 and 9 It is possible to perform highly selective tuning amplification and ideal frequency conversion in the intermediate frequency band.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A receiver system of FIG. 1, which is an embodiment of the present invention, will be described with reference to FIG. The received signal enters the buffer amplifier 2 through the antenna 1 and frequency selective tuning reception is performed by the phase-locked oscillation loop composed of the phase comparator 4 and later. In the h1 part of FIG. 1, the clock frequency of 22 is determined by the instruction input of 24, so that the phase comparator of 20
The oscillation frequency of the local oscillator configured by the phase-locked oscillator including the control filter 19 and the voltage (current) control oscillator 11 is set. Since this local oscillator output is input to the frequency converters 7 and 9 which are the components of the phase-locked oscillation loop composed of the phase comparator 4 and later, the local oscillator frequency and the intermediate frequency band filter (8) Phase synchronization is performed by tuning to the phase comparator input signal frequency of 4 corresponding to the sum of intermediate frequencies. Therefore, 4 phase comparators, 5 control filters, 6 voltage (current) controlled oscillators, 7 frequency converters, 8 intermediate frequency band amplifiers,
The phase-locked loop made of 9 frequency converters and 10 band amplifiers (intermediate frequency + local oscillation frequency) can be used as a selective tuning type high frequency tuning amplifier mainly determined by 8 bands. Further, the output of the intermediate frequency band amplifier 8 in FIG. 1 is input to the angle modulation detector 8c via the amplitude limiting amplifier 8b, and the demodulation signal 25 is obtained.

FIG. 2 shows another embodiment of the present invention.
11 between the local oscillation signal and the frequency converters 7 and 9 which are components of the phase locked loop.
The present invention relates to a method for arbitrarily adjusting the phase difference between the signal fed back to the phase comparator 4 and the input signal from the amplifier 2 by inserting 1 or p-2. For example, in FIG.
As the intermediate frequency band amplifier 8 of 1), the intermediate frequency band filter 8-1 shown in FIG. 2 (h2), the phase comparator 8-2, the control filter 8-3, and the voltage (current) 8-4.
When a phase-locked oscillator using a controlled oscillator is used, the phase shifter p-1 may be delayed by 90 degrees and the phase shifter p-2 may be set to 0 degree.

FIG. 3 shows an embodiment in which an antenna and a frequency converter are installed in a remote place such as outdoors, and FIG. 3 (h1)
Are 22 clock signal generators, 20 phase comparators, 19
Control filters, 18 voltage (current) controlled oscillators, 2
1 is a frequency divider, 24 is a control signal for frequency setting, 23
Is a binary noise generator, 17 is a two-phase modulator, 16 is a buffer amplifier, 14 is a cable line for transmitting and receiving signals, 15 is an intermediate frequency signal receiving device, and FIG. 3 (h1) is a local oscillation frequency setting. The present invention relates to a device for generating a frequency control signal by a spread spectrum modulation method for, and demodulating it by a control signal receiver 12 via cable lines 14 and 13 to set a local oscillation frequency of 11. In this embodiment, the local oscillation frequency is determined by 24 control inputs, and therefore the input signal from the antenna is frequency-selectively tuned by a phase-locked loop of 4 or less to convert the frequency and then the cable lines 13 and 14 are converted.
The present invention relates to a signal receiving system for transmitting to 15 intermediate frequency receiving units via the.

[0009]

As shown in the embodiments of FIGS. 1, 2, and 3, by designating a local oscillation frequency, a phase-locked oscillator for simultaneously performing high-frequency selective tuning and frequency conversion for a desired received signal frequency is constructed. , High frequency (0, 5-50G
Even in HZ), high selectivity (narrow band) reception is possible, and if satellite broadcast TV radio waves are received by the method of FIG. 3, compared to the conventional method that requires frequency conversion twice, the local oscillation frequency It is possible to solve the drift problem and improve the performance by reducing the transmission loss due to the cable. Also, by inserting a phase shifter in series with the local oscillator as in the case of FIG. 2, the mutual phase relationship between the input signal and the feedback signal in the comparator of the phase locked loop can be adjusted arbitrarily, and the stability of the phase locked loop can be stabilized. The degree of freedom in design such as improvement of the property is increased.

[0010]

[Brief description of drawings]

FIG. 1 shows an example of a system diagram of a signal receiving apparatus according to the present invention.

FIG. 2 shows a system diagram of an application example of a signal receiving apparatus according to the present invention.

FIG. 3 is a system diagram 1 of an application example of a signal receiving apparatus according to the present invention.
Here is an example:

Claims (5)

[Claims] 1. A phase comparator 4, a control filter 5, a voltage (current) controlled oscillator 6, a frequency converter 7, and an intermediate frequency band amplifier 8 shown in FIG. 1 as a method of constructing a phase locked oscillator synchronized with a received signal. Frequency converter 9, frequency converter 9
10, the local oscillator 11 for guiding the output of the
And a local oscillator control device 22 for performing phase-tuned reception of a desired reception frequency and frequency conversion at a designated local oscillation frequency. 2. The frequency converter according to claim 1, wherein the path 10 in FIG. 1 is used as a desired received signal band filter and the detected comparison signal is fed back to the comparator 4. 3. A local oscillating device as shown in FIG. 2, a method of inserting a phase shifter p-1 or p-2 in series with the device 11, and means for inserting phase shifters p-1 and p-2 at the same time. The receiver according to claim 1 or 2, wherein the establishment and stability of the phase-locked operation are measured by adjusting the phase angle of the phase-locked loop. 4. A phase-locked oscillating device for band-selecting an intermediate frequency and performing phase-locked oscillating as shown in FIG. 2 (h2), and a local oscillating device 11, a phase shifter p-1 or p-2.
A receiving device that performs tuning reception of a desired signal and frequency conversion by a phase-locked oscillation device that is configured by connecting. 5. A frequency designation control signal shown in FIG.
A frequency spread control signal configured to include a carrier wave generator 18, a binary noise generator 23, and a two-phase (multi-phase) phase modulator 17, whose oscillation frequency is determined by the frequency designation control input 24, is transmitted. 5. The receiving device according to claim 1, wherein the local oscillation frequency control device demodulates the spread spectrum modulated signal to control the designation of the local oscillation frequency.